The present invention relates to novel substituted piperazines and derivatives thereof useful as pharmaceutical agents, to methods for their production, to pharmaceutical compositions which include these compounds and a pharmaceutically acceptable carrier, and to pharmaceutical methods of treatment. The novel compounds of the present invention are central nervous system agents. More particularly, the novel compounds of the present invention are dopaminergic agents.
EP 0 211 457 A2 discloses compounds of formula: ##STR2## wherein R is hydrogen, halo, C.sub.1-6 -alkyloxy, hydroxy or phenyl; m is 2 or 3; R.sup.1, R.sup.2, R.sup.3, R.sup.4 are each independently hydrogen or C.sub.1-6 -alkyl or where R.sup.3 and R.sup.4 are substituted on a different carbon atom, R.sup.3 and R.sup.4 taken together may form a bivalent radical --CH.sub.2 --CH.sub.2 --; R.sup.5 is (aryl)C.sub.2-6 -alkenyl, (aryl)C.sub.2-6 -alkynyl, (aryl)(hydroxy)C.sub.1-6 -alkyl or (aryl)(oxo)C.sub.1-6 -alkyl; the n-oxide forms; and pharmaceutically acceptable acid addition salts and the possible stereochemically isomeric forms thereof having antitussive/analgesic properties.
GB 1055548 discloses compounds of formula ##STR3## wherein R represents unsubstituted phenyl or phenyl substituted by methyl, halogen, nitro, amino, (lower alkanoyl)amino, or lower alkoxyl; and either A is alkyl of 1 to 4 carbon atoms and A' is alkyl of 1 to 4 carbon atoms, benzyl, chlorobenzyl, or dimethoxybenzyl; or A and A', together with the adjacent nitrogen atom, form one of the following heterocyclic rings: pyrrolidino, morpholino, thiomorpholino, 4-phenylpiperidino, 4-phenyl-4-hydroxypiperidino, N'-methylpiperazino, N'-benzylpiperazino, N'-phenylpiperazino, N'-chlorophenylpiperazino, N'-tolylpiperazino, N'-methoxyphenylpiperazino, N'-(.beta.-hydroxyethyl)piperazino, N'-(.beta.-acetoxyethyl)piperazino, N'-(.beta.-propionyloxyethyl)piperazino, N'-carbethoxypiperazino, hexamethyleneimino, and heptamethyleneimino; provided that when R is phenyl, p-methoxyphenyl, o- or p-nitrophenyl, or o-aminophenyl, ##STR4## does not represent dimethylamino or diethylamino; and their acid addition salts, especially those containing physiologically innocuous anions having antiulcer activity.
The aforementioned references do not teach nor suggest the combination of structural variations of the compounds of the present invention nor their use as dopaminergic agents described hereinafter.